It is time to advance the (Gateway Tunnel) program now. There is no comfort zone to say we don't need to be worried, Anthony Coscia, Amtrak.

Amtrak's 104-year old Hudson River tunnels are running on borrowed time and need to be shut down for a year each to repair the damage received from Hurricane Sandy flooding, according to transit officials.

To avoid any commuting nightmares during these major repairs, Amtrak officials say two new "Gateway" tunnels must be built.

Both Hudson River tunnels and two tunnels under the East River sustained enormous amounts of damage, from Sandy driven flooding, which would require substantial repairs to concrete bench walls, track and other infrastructure, Anthony Coscia, chairman of Amtrak's board of directors said during a discussion of a consultant's report about tunnel conditions on Wednesday.

The report is the first detailed look at the extent of damage to the Hudson and East river tunnels.

"The shell of the tunnel...is in sound, safe condition. We wouldn't run a single train if the tunnels weren't safe," Coscia said. "It is time to advance the (Gateway Tunnel) program now. There is no comfort zone to say we don't need to be worried."

Corrosion from the sulfates and chloride left behind, after sea water was pumped out, is deteriorating concrete bench walls along side the tracks, the electrical wiring inside them and the tracks themselves, said Stephen Gardner, vice president of Northeast Corridor Infrastructure and Investment Development.

"Over time, something won't function and we won't be able to run a train through them," Coscia said.

Amtrak proposed the Gateway Tunnel project, in February 2011, which includes building two new Hudson River tunnels to Penn station, four tracks through the New Jersey Meadowlands, replacement of the trouble prone 100-year-old Portal Bridge and construction of a New York Penn Station south to handle additional passengers. Amtrak officials declined to give an exact price tag, only saying it would range in the multiple billions of dollars.

Gateway was proposed after Gov. Chris Christie canceled the "Access to the Region's Core" tunnel project in October 2010 due to concerns about cost increases.

Losing one of the current tunnels would be a commuting nightmare, but getting financial support for Gateway will be be difficult, said Len Resto, New Jersey Association of Railroad Passengers president.

"The situation gets more dire day by day," Resto said. "You will get delays unacceptable to the riding public and it will become an economic factor. There's only so much that employers will put up with if people can't get to work on time."

A report by consultant HTNB about the tunnel conditions has been shared with the Congressional delegation of both states.

"Riders have to tell their Congress people that this has to be fast tracked," Resto said.

The report found that salt will continue to deteriorate infrastructure in the old tunnels, which will make train service more prone to delays. On Aug. 19, a piece of bench wall fell on to the tracks, requiring emergency repairs and causing delays. HTNB warned similar incidents are likely as corrosion continues.

To do the major repair work, one tube of the two Hudson River tunnels would have to be shut down for a year, which would have severe impact on the 450 trains a day which use the tunnels. Coscia said that can only happen if the Gateway Tunnel project is built first, which would allow Amtrak to take one of the old tunnels out of service without reducing the number of trains it and NJ Transit run.

"The tunnels are so busy, our ability to stop traffic (for repairs) is limited," Coscia said. "A new tunnel would allow us to shift traffic."

Transit advocates said the tunnels should be built before any other part of the Gateway project.

"When Amtrak says tunnels are so important, that's what they'll build first and they won't push for Penn Station South, when they give up on that for the time being, they will have a lot more credibility," said David Peter Alan, chairman of the Lackawanna Commuter Coalition.

Coscia would not commit to building tunnels first. "It's not responsible to say we'll create one (Gateway) component without the rest," he said.

Until a new tunnel is built, interim repairs call for pressure washing the tunnel to remove salt, removing damaged and loose concrete, coating exposed steel, sealing all cracks and pressure washing and patching holes in the concrete tunnel lining more than one inch deep.

The $689 million major repair project requiring a tunnel shut down, would replace and rebuild tunnel bench walls, tracks and roadbed. That price tag doesn't include replacing electrical and mechanical systems inside the tunnels. That work can't be done a few hours during the overnight or during weekends, which is when tunnel maintenance and repairs currently are done, Gardner said.

Amtrak officials are looking to insurance money to fund all or most of that work, Gardner said.

Work on the two damaged East River tunnels, used by the Long Island Rail Road and by NJ Transit trains which are stored in the Sunnyside Yard in Queens, will be the first major repair project. Three tunnels will remain open between Manhattan and Queens, with one closed for repairs, Gardner said.

Design work is starting for the Hudson River tunnel repairs Environmental and preliminary design work on Gateway also has been funded and has started.